Method and apparatus to facilitate image difference transmission while maintaining image salience

Abstract

One embodiment of the present invention provides a system to facilitate image difference transmission for images in a video system. The system operates by receiving a video stream that includes a sequence of images. The system transforms a first frame of the sequence of images using a transform function to create a first transformed image. Note that this transform function places the image salience in the larger coefficients. The system also transforms a second frame using the same transform function to create a second transformed image. The system then subtracts the second transformed image from the first transformed image to create a difference-transformed image. The coefficients are arranged in order of size, from larger to smaller. Smaller coefficients, that are less than a specific threshold, are removed from the difference-transformed image so that this difference-transformed image can be stored and transmitted with reduced bandwidth while maintaining image salience.

What is claimed is:  
     
         1 . A method to facilitate image difference transmission for images in a video system, comprising: 
 receiving a video stream, wherein the video stream includes a sequence of images;    transforming a first frame of the sequence of images using a transform function to create a first transformed image, wherein the transform function places image salience in larger coefficients;    transforming a second frame using the transform function to create a second transformed image;    subtracting the second transformed image from the first transformed image to create a difference-transformed image; and    removing smaller coefficients from the difference-transformed image, whereby the difference-transformed image can be stored and transmitted with reduced bandwidth while maintaining image salience.    
     
     
         2 . The method of  claim 1 , further comprising: 
 coupling the difference-transformed image to an image reconstructor;    adding the first transformed image to the difference-transformed image to create a reconstructed transformed image; and    performing an inverse transform function on the reconstructed transformed image to create a reconstructed second frame.    
     
     
         3 . The method of  claim 2 , wherein the reconstructed second frame does not exhibit visual degradation to a human visual system.  
     
     
         4 . The method of  claim 2 , wherein coupling the difference-transformed image to the image reconstructor involves coupling the difference-transformed image through a storage medium.  
     
     
         5 . The method of  claim 2 , wherein coupling the difference-transformed image to the image reconstructor involves coupling the difference-transformed image across a network.  
     
     
         6 . The method of  claim 5 , wherein the network includes the Internet.  
     
     
         7 . The method of  claim 1 , wherein the transform function is a discrete wavelet transform function.  
     
     
         8 . The method of  claim 1 , wherein the sequence of images includes one of a stream of pictures and a stream of three-dimensional renderings.  
     
     
         9 . A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method to facilitate image difference transmission for images in a video system, the method comprising: 
 receiving a video stream, wherein the video stream includes a sequence of images;    transforming a first frame of the sequence of images using a transform function to create a first transformed image, wherein the transform function places image salience in larger coefficients;    transforming a second frame using the transform function to create a second transformed image;    subtracting the second transformed image from the first transformed image to create a difference-transformed image; and    removing smaller coefficients from the difference-transformed image, whereby the difference-transformed image can be stored and transmitted with reduced bandwidth while maintaining image salience.    
     
     
         10 . The computer-readable storage medium of  claim 9 , the method further comprising: 
 coupling the difference-transformed image to an image reconstructor;    adding the first transformed image to the difference-transformed image to create a reconstructed transformed image; and    performing an inverse transform function on the reconstructed transformed image to create a reconstructed second frame.    
     
     
         11 . The computer-readable storage medium of  claim 10 , wherein the reconstructed second frame does not exhibit visual degradation to a human visual system.  
     
     
         12 . The computer-readable storage medium of  claim 10 , wherein coupling the difference-transformed image to the image reconstructor involves coupling the difference-transformed image through a storage medium.  
     
     
         13 . The computer-readable storage medium of  claim 10 , wherein coupling the difference-transformed image to the image reconstructor involves coupling the difference-transformed image across a network.  
     
     
         14 . The computer-readable storage medium of  claim 13 , wherein the network includes the Internet.  
     
     
         15 . The computer-readable storage medium of  claim 9 , wherein the transform function is a discrete wavelet transform function.  
     
     
         16 . The computer-readable storage medium of  claim 9 , wherein the sequence of images includes one of a stream of pictures and a stream of three-dimensional renderings.  
     
     
         17 . An apparatus to facilitate image difference transmission for images in a video system, comprising: 
 a receiving mechanism that is configured to receive a video stream, wherein the video stream includes a sequence of images;    a transforming mechanism that is configured to transform a first frame of the sequence of images using a transform function to create a first transformed image, wherein the transform function places image salience in larger coefficients;    wherein the transforming mechanism is further configured to transform a second frame using the transform function to create a second transformed image;    a subtracting mechanism that is configured to subtract the second transformed image from the first transformed image to create a difference-transformed image; and    a removing mechanism that is configured to remove smaller coefficients from the difference-transformed image, whereby the difference-transformed image can be stored and transmitted with reduced bandwidth while maintaining image salience.    
     
     
         18 . The apparatus of  claim 17 , further comprising: 
 a coupling mechanism that is configured to couple the difference-transformed image to an image reconstructor;    an adding mechanism that is configured to add the first transformed image to the difference-transformed image to create a reconstructed transformed image; and    an inverse transform mechanism that is configured to perform an inverse transform function on the reconstructed transformed image to create a reconstructed second frame.    
     
     
         19 . The apparatus of  claim 18 , wherein the reconstructed second frame does not exhibit visual degradation to a human visual system.  
     
     
         20 . The apparatus of  claim 18 , wherein coupling the difference-transformed image to the image reconstructor involves coupling the difference-transformed image through a storage medium.  
     
     
         21 . The apparatus of  claim 18 , wherein coupling the difference-transformed image to the image reconstructor involves coupling the difference-transformed image across a network.  
     
     
         22 . The apparatus of  claim 21 , wherein the network includes the Internet.  
     
     
         23 . The apparatus of  claim 17 , wherein the transform function is a discrete wavelet transform function.  
     
     
         24 . The apparatus of  claim 17 , wherein the sequence of images includes one of a stream of pictures and a stream of three-dimensional renderings.